<!DOCTYPE html>
<head>
    <meta charset="UTF-8">
    <title>jQuery选择器</title>
    <script type="text/javascript" src="js/jquery-3.3.1.js"></script>
    <script type="text/javascript">
        $(function(){
            $("*")
            $("#one")
            $(".two")
            $("div")
        });
    </script>
</head>
<body>
    <div id="one">Category: Selectors</div>
    <div class="two">Category: Selectors</div>
    <div class="two">Category: Selectors</div>
</body>
</html>